Electrical transformer.



No. 639,505. Patented Dec. l9, I899. A. F. BERRY.

ELECTRICAL TRANSFORMER.

(Application filed June 16, 1897.) (No Model.)

3 Sheets-Sheet I Patented Dec. 19, I899.

A. F. BERRY.

ELECTRICAL TRANSFORMER.

(Application filed June 16, 1397.) (No Model.) 3 She efsSheet 2,

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UNITED STATES PATENT ()FFICE...

ARTHUR FRANCIS BERRY, OF MARKET-HAREOROUGH, ENGLAND.

ELECTRICAL TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 639,505, dated December 19, 1899.

Application filed June 16, 1897. Serial No. 641,025. (No model.)

To all whom it HY/6L1] concern:

Beit known that I, ARTHUR FRANCIS Bun- RY, a subject of the Queen of Great Britain and Ireland, residing at Ashley, Market-Han borough, in the county of Leicester, England, have invented Improvements in Electrical Transformers, of which the following is a specification, and for which Letters Patent have been granted in the following countries, namely: Great Britain, No. 2,801, dated February 2, 1897, and No. 9, 157, dated April 13, 1897; France, No. 275,341, dated February 25, 1898; Belgium, No. 134,250, dated March 1, 1898; Italy, Vol. XOIV, No. 190, dated March 31, 1898; Austria, No. 48/2323, dated April 27, 1898; New South ales, No. 8,698, dated September 30, 1898, and South Australia, No. 4,179, dated September 27, 1898.

This invention has reference to an improved construction of electrical transformer built up of laminated metal plates arranged radially around a center to form a cylindrical or other suitably-shaped core or casing having within it an endless space, passage, or way of annular, polygonal, or equivalent shape, wherein the primary and secondary windings are placed.

In the accompanying drawings, Figures 1, 2, and 3 show, respectively, in vertical section, in plan, and in horizontal section one construction of transformeraccording to this invention. Figs. 4 and 5 are elevations at right angles to each other; and Fig. 6, a plan showing to a larger scale than Figs. 1, 2, and 3 one of the laminated metal plates used in the construction of such a transformer. Figs. 7, 8, and 9 are similar views to Figs. 4, 5, and 6, respectively, showing a modified construction of laminated metal plate. Fig. 10 is a plan showing a modified form of my improved transformer. Figs. 11 and 12 are vertical sections showing diagrammatically other modifications.

The transformer shown comprises a series of laminated metal plates 1, arranged radially around a center and each provided with an opening 2, so that when all the plates are placed together, as shown, they form an ap proximately cylindrical or star-shaped core or casing having within it an endless space,

passage, or way 3 of annular shape, wherein the primary and secondary windings -1 and 5, respectively, are placed.

Each of the laminated metal plates 1 is built up of a number of straight strips or stampings 1 1 1 1, Figs. 4, 5, and 6, of thin sheet-iron arranged at right angles to one another, so as to form a hollow rectangular builtup plate or frame, the metal strips composing each side of which are so arranged that the alternate strips overlap one another at the ends, as shown, the projecting ends 1 of each of two adjacent series of strips entering the spaces 1 between the projecting ends 1 of the opposite or adjacent series of strips, so as to become bonded or jointed therewith and form butt and lap joints alternately, whereby a cry efficient magnetic circuit is ob tained and eddy-curren ts prevented. \Vithin the diverging or angular spaces between the radial plates 1 are or may be arranged other or additional similarly-constructed plates 1, the radial width of which may be approximately equal to but is preferably less than the main .plates between which they are placed, so as to leave, as shown, ventilatingspaces 7, extending lengthwise of the core. The spaces betwen these two series of plates may, according to the size of the transformer, be fitted with other similarly constructed plates or by metal strips. The width of the sides of the hollow frame-like plates may be equal or unequal, as may be desired in any particular case; but the rectangular openings 2 in the several plates are made equal or approximately equal in width radially and arranged to correspond with one another, so as to form the annular space or way 3 for the primary and secondary windings 4 and 5, which are left partly exposed between the plates, as shown.

The laminated metal plates shown in Figs. 7, 8, and 9 are of hollow rectangular shape, like those shown in Figs. 4, 5, and 6, but are built up of L-shaped stampings 1 1 ,of sheetiron, one set of these stampings being arranged to form the inner side and one end of the said annular space or chamber 3 and the other set to form the outer side and other end of the space or chamber. The two L-shaped plates comprising each plate are preferably arranged in the reverse manner to those in adjacent plates, so as to break joint therewith, as shown, and form butt and lap oints alternately. The radial spaces formed between the plates 1 when these are assembled together may advantageously be fitted with additional hollow rectangular plates composed of L-shaped stampings like the main plates, but having their long sides narrower than those of the said main plates.

The stampings shown in Figs. 7, 8, and 9 may advantageously be formed out of rectangular sheets of iron, from each of which there can be out four L,-shaped stampings, two of which are adapted to be placed thus El and two thus 13 leaving a rectangular-shaped piece of metal suitable forother purposes, so that all waste of material will be obviated.

As will be obvious, the arrangement of the laminated iron plates 1 can be variously m odified. Thus four laminated iron plates 1 may touch each other at their adjacent edges, so as to form, as seen in plan or end View, Fig. 10, a cross with a central hollow passage between them of square section. Between these four plates four smaller plates l may be arranged, and between the two sets of plates a still smaller set of plates, and so on, if necessary, longitudinal ventilating-spaces being left between the several plates.

In building up my improved transformer with metal plates constructed as shown in Figs. 4:, 5, and (l the inner series of metal strips 1 may be arranged around a core and be surrounded with a layer 8 of insulating material. One half of the secondary coil 5 is then wound around these insulated strips 1, after which the primary winding 4, the other half of the secondary winding 5, and an outer layer 9 of insulating material are applied, layers 8 8 of insulating material being arranged at the top and bottom, respectively, of the windings.

The outer strips 1 and top 5 and bottom strips 1 1 are then placed in position, so that their ends become bonded toi gether, and the whole suitably secured together, so as to inclose and surround the formed by and between the several built-up plates.

In building up my improved transformer lly my invention electrical transformers possessing a high efficiency can be easily, cheaply, and conveniently made with plenty of ventilating-spaces, into which may be dissipated in the best possible manner the energy necessarily wasted in the copper and iron of the transformer. The ventilatingspaces 11 may, especially in the case of large transformers, be partially or wholly filled with tubes of thin non-magnetic material, such as copper, having a blackened or dead outer surface capable of readily absorbing radiant heat, such tubes being tilled or traversed by a suitable substance-for example, water or oilto carry olf the heat, the arrangement resembling a water-tube boiler in which the heating is effected by electricallyproduced heat. \Vhen wateror oil is caused to flow through the tubes, the ends of the transformer may be provided with chambers. Fig. 11 shows in vertical section an arrangement of this kind, wherein 12 are coppertubes coated, for example, with a mixture of lampblack and an oil or a varnish and arranged in the angular spaces 11 between the plates 1 1, the said tubes being connected at their 3 ends to chambers 9 9, formed in the end plates 9 through which and the tubes water or oil is caused to flow. For this purpose two chambers may be connected by an external pipe 13, (or pipes,) which may be coiled, or by an annular chamber 13, which may have corrugated surfaces to increase the coolingsurface, the said pipe or pipes or chamber being arranged to pass through the air or other cooling medium external to the transformer-core, or the lower chamber may be connected to a water-main and the upper one with an exhaust-pipe.

Fig. 2 shows, partly in section and partly in elevation, a modified arrangement in which the vertical tubes 12 are connected at the top to a flat coiled pipe 12 and at the bottom to a wheelshaped casting 9 the pipe 12 and j casting being connected by an external coiled With L-shaped stamping the inner series of such stamping are placed in position and the primary and secondary windings placed L-shaped stampings are suitably secured in position around the inner series, so as to inclose the primary and secondary windings, which are suitably insulated, as before, from the built-up plates.

At the inner periphery of the core or body, where the stampings preferably bear against each other, there may be a tubular or ringlike support or supports.

cooling pipe 13". The chambers 9 9" or casting 9 as the case may be, can be formed with removable plates or screw-plugs to enable ready access to be obtained to their interiors to admit of the tube ends being readily secured in place by expanding or otherwise.

\Vhat I claim is- 1. An electrical transformer comprising primaryand secondary coils, an iron core composed of a number of comparatively thin iron plates having holes therethrough of uniform width and each built up of a number of pieces around them, after which the outer series of of thin sheet-iron having their adjacent ends arranged to form butt and lap joints alternately, said plates being arranged to surround said coils and leave a longitudinal air-passage through the core and spaced apart so as to leave between adjacent plates longitudinal air-passages surrounding the coils, and layers of insulating material. inserted between the coils and between the coils and the adjacent edges of the plates, substantially as described.

2. An electrical transformer comprising an iron core built up of laminated plates each having a large central opening therethrough and composed of a number of pieces of thin sheet-iron having their adjacent ends arranged to form butt and lap joints alternately, said plates being grouped about a center so as to leave a central air-passage between their adjacent ends and air-passages of angular section between their adjacent sides and held in position by a wrapping of insulating material extending through the holes in said plates,primary and secondary coils extending through said holes, and layers of insulating material between said coils and the outer, upper and lower edges of the holes through which said coils extend, substantially as described.

3. An electrical transformer comprising an iron core built-up of sets of laminated plates each having a large central hole therethrough and composed of a number of pieces of thin sheet-iron having their adjacent ends arranged to form butt and lap joints alternately, one of said sets of plates being grouped about a center so as to form a central air-passage between their adjacent ends and diverging air-spaces between their adjacent sides and the other set or sets of plates being arranged in the diverging spaces between the firstmentioned set of plates and so as to leave airspaces between them and such other plates, a wrapping of insulating material extending through the holes in said plates and acting to hold the latter together at the center, primary and secondary coils extending through the holes in said plates, and insulating material between said coils and between said coils and the edges of the holes through which they extend, substantially as described.

ei. An electrical transformer comprising an iron core built up of thin laminated iron plates grouped together around a center so as to form a central and a number of diverging longitudinal air-spaces between them, primary and secondary coils extending through said plates and insulated from the edges of the holes through which they pass, perforated end plates between which said laminated plates are clamped, the'perforations in said plates being opposite the longitudinal airspaces in said core, and hollow supports arranged within the ends of the central airspace formed by the adjacent end of said plates, substantially as described.

5. An electrical transformer comprising a number of laminated iron plates arranged radially around a center and each built up of four groups of straight flat strips of thin sheet-iron arranged at right angles to each other so as to form a hollow rectangular plate or frame the metal strips composing each 1 group being so arranged that the alternate strips overlap one another at the ends and the projecting ends of each group of strips enter the spaces between the projecting ends of adjacent groups of strips so as to become bonded or jointed therewith and form butt and lap joints alternately, said plates being of different radial widths and spaced apart so as to form longitudinal ventilating-spaces between them but having the openings there through all of the same radial width, and primary and secondary windings extending through the annular passage or way formed by the openings in the said plates, substantially as described.

6. An electrical transformer comprising an iron core built up of a number of laminated iron plates of practically uniform thickness arranged radially around a center so as to form a central air-passage 7* and outer diverging air-passages S, and each composed of groups 1, 1 1, 1 of straight fiat strips of thin sheet-iron arranged together so that the projecting ends of each group of strips enter the recesses left between the projecting ends of adjacent groups of strips and so as to form a rectangular opening in the plate, the several openings being of equal radial width and arranged in a circular row, primary and secondary windings extending through the openings in the plates, inner and outer layers 8 and 9 and upper and lower layers 8 and 9 of insulating material arranged between said coils and plates, perforated end plates between which the said laminated plates are held, the perforations in said end plates being opposite the longitudinal air-passages in said core, and central end supports 10 within the central air'passage, substantially as described.

7. In an electrical transformer, the combination with primary and secondary coils and vertically-arranged laminated metal plates spaced apart and surrounding said coils, of end plates between which said plates and coils are held and which are formed with chambers one of which is provided with one or more inlets and the other with one or more outlets for liquid, and vertical tubes arranged in the spaces between said laminated metal plates and connected at their ends to said chambers, substantially as and for the purpose described,

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR FRANCIS BERRY.

Witnesses:

PERCY E. MATTOCKS, HUGH HUGHES. 

